1. Introduction
Conventional right ventricular
pacing (RVP) can cause electrical and mechanical dyssynchrony and is
associated with increased risks of cardiac remodeling, pacemaker-induced
cardiomyopathy, heart failure, and mortality.1, 2These deleterious effects have driven the search for alternative pacing
sites. Conduction system pacing (CSP) is one such alternative that aims
to directly activate the His-Purkinje conduction system thereby
preserving synchronous ventricular activation and is thus deemed to be a
more physiological alternative to conventional RVP.
Left bundle branch area pacing (LBBAP), proposed by Huang et al. in
2017,3 has emerged as a new physiological conduction
system modality that has a lower, more stable threshold and achieves a
paced QRS duration similar to that of His bundle pacing
(HBP).4 LBBAP presents a simpler implantation
technique, shorter fluoroscopy duration, and a procedure time with a
steeper learning curve compared to HBP; thus, LBBAP is currently widely
used as an alternative for CSP and considered the first strategy for
patients in whom a high burden of ventricular pacing is
anticipated.5, 6
In most cases, LBBAP has been performed exclusively using a lumenāless
lead (LLL) with a fixed helix design (SelectSecure 3830 pacing lead,
Medtronic Inc., Dublin, Ireland) and a pre-shaped sheath dedicated to
this lead (C315His, Medtronic Inc.),3, 7 both of which
are unavailable in some centers and countries. Meanwhile, De Pooter et
al. reported their early experience with LBBAP using a standard
stylet-driven lead (SDL) in 20 cases, and the initial results showed
feasibility and safety.8 However, most researches have
reported initial experience with LBBAP, and only few studies have
focused on the learning curves for LBBAP. Moreover, no data exists on
the learning curve for LBBAP with SDL. In this study, we aimed to
evaluate the success rate, fluoroscopy and procedure time, lead and
electrocardiography (ECG) parameters, and learning curve of LBBAP using
SDL, and to compare these parameters with those of conventional RVP.